Question

The standard Gibbs energies of formation of ions are reported on a scale in which"

A) They are always negative
B) They are always positive
C) They are referenced to the Gibbs energy of water
D) They are referenced to the Gibbs energy of air

Answer 1

The standard Gibbs energies of formation of ions are referenced to the Gibbs energy of water.

Step-by-step explanation:

The standard Gibbs energies of formation of ions are referenced to the Gibbs energy of water. Ions in aqueous solution have their standard free energies relative to the hydrated hydrogen ion H+ (aq) which is assigned AG = 0. The standard free energy of formation (AG) of a compound is the change in free energy that occurs when 1 mol of a substance in its standard state is formed from the component elements in their standard states. By definition, the standard free energy of formation of an element in its standard state is zero at 298.15 K.